Index Storage Structure
By default, indexes are created with an ISAM storage structure. There are two methods to override this default:
• To specify the default index storage structure for indexes created during the session, use the -n flag when issuing the command that opens the session (connect). For more information about this flag, see the Ingres System Administrator Guide.
• To override the session default when creating an index, specify the desired storage structure using the structure option when issuing the create index statement.
To specify whether the index is to be compressed, use the
with [no]compression clause. By default, indexes are not compressed. If with compression is specified, the
structure clause must be specified. An RTREE index cannot be compressed. To change the storage structure of an index, use the modify statement. For more information about table storage structures, see
Modify Statement (see
Modify Statement).